Blender rigged horse - foot gets stuck to the ground when moving the animal
The mesh is wrongly skinned to the Armature. Vertices of the bottom parts of the legs are probably influenced by root bone. To avoid that you should turn off Deform on the root bone (you should also turn it off on the IK target bones), clear bone groups, that was created by Parenting with automatic weights,delete Armature modifier and clear parent from the mesh. Then repeat parenting with automatic weights and you'll be good to go. Below you'll find image with the placement of Deform option in bone properties.